After the Department of Justice recently issued a scathing report saying police in the country's third-largest city routinely violated the Constitution by using excessive force against residents, many activists cheered for the inevitable reforms — and federal oversight — they expected to follow.

The findings on Chicago officers set the stage for the city to negotiate a court-enforced agreement with the federal government, called a consent decree, to change how it polices while officials in Washington keep tabs. Police reform advocates applauded a similar pact Justice officials recently announced with Baltimore after the department found that city's officers discriminated against blacks.

Some police say the government has been heavy-handed, and that its agreements with cities have cost too much and taken too long to implement. Some activists say the agreements, which often require extra trainingin use of force and better tracking of personnel issues, don’t go far enough.

But over the nearly 20 years the Justice Department has gone to court to force changes in police agencies in more than two dozen cities, the results have largely been positive, according to data and criminologists.

“Having been in policing for 34 years, consent decrees certainly do work,” said Ronal Serpas, a criminal justice professor at Loyola University New Orleans who was the city’s police chief in 2012 when it signed on to ongoing reforms. “These agreements give you a road map, though it doesn’t mean things change with the snap of a finger.”

In Baltimore, a pending agreement with the Department of Justice that awaits court approval was announced amid ongoing tensions over the death of Freddie Gray, a 25-year-old black man who died from a spinal cord injury after his arrest in 2015. Among other things, the pact would require a community oversight task force for police in addition to officer training in deescalation and implicit bias.

But while the Justice Department rushed to release its Chicago report and make its Baltimore announcement in the waning days of Barack Obama’s presidency in hopes of ensuring reforms, experts say the road ahead is unclear in the Trump administration.

"There can be backsliding,” said Samuel Walker, a former University of Omaha criminal justice professor who specializes in police accountability. "One thing it often depends on is who is leading police and how much they invest in change.”

On the national level, that’s the attorney general, the top law enforcement official.

Under Obama, the Justice Department entered into agreements with 12 police departments, four times as many as under President George W. Bush.

Trump's pick for attorney general, Republican Sen. Jeff Sessions of Alabama, said during his confirmation hearing that current decrees with police departments would “remain in force until and if they are changed,” adding that they were not “necessarily a bad thing.”

But Sessions also said there’s “concern that good police officers and good departments” get punished because of a few bad ones.

In 2008, he had stronger words. Consent decrees are “dangerous,” he wrote, calling them “exercises of raw power” that “constitute an end run around the democratic process.”

Serpas, who left New Orleans police in 2014, said that he understood concerns but that “if policing improves in the end, it’s certainly worth it.”

In its investigation of Serpas’ officers, the Justice Department said they had a pattern of racial profiling, excessive force and unconstitutional stops and arrests. In a September report, an outside monitor described a “remarkable turnaround” in how police worked with sexual assault victims and praised body camera efforts. The monitor also said police still needed to do more to improve community relations.

Experts say it’s too early to assess the results of consent decrees signed in recent years for cities such as Cleveland, or Ferguson, Mo., where the police shooting of Michael Brown fueled the Black Lives Matter movement.

An independent lawyer hired to monitor Ferguson’s progress said last month that the city had missed recent deadlines to set up new policies in basic policing issues but was still acting in “good faith” toward improvements, such as through a new policy on use of force and an ordinance from the city to create a civilian review board to look at police misconduct complaints.

While many pacts are set up for five years — with the costs of outside monitoring footed by the cities — they can be extended to last much longer if officers don’t improve. In Oakland, police have worked for 13 years under monitoring stemming from findings of racial profiling and police brutality.

Congress gave the federal government the power to police local law enforcement departments in 1994, after national outrage grew over the 1991 beating of Rodney King in Los Angeles. The law lets the government sue local police if they don’t comply with reforms.

It was 1997 before Pittsburgh became the first city to enter a consent decree after the American Civil Liberties Union filed suit over police abuses. The results there have been mixed. Use of force has gone up and down over the years, and a series of high-profile incidents, including a 2012 shooting of an unarmed black man that left him paralyzed, have tarnished the department’s image.

Chuck Wexler, executive director of the Police Executive Research Forum, pointed to a Department of Justice agreement with Los Angeles as a model.

The city was under monitoring for 12 years after investigations by the Justice Department over civil rights violations, including routine false arrests and excessive force. The agreement, which ended in 2013, pushed for better training of officers and tracking of misconduct, among other requirements.

In a 2009 review, Harvard criminal justice professors found the “quality of enforcement activity” among police had improved, with stops more frequently leading to arrests, and arrests more frequently leading to charges. Public approval had also gone up, with residents saying they were less fearful of crime and more trusting of police. Still, black and Latino residents were more likely than whites to say they were unsatisfied, and protests over police tactics and shootings have persisted.

“The process with these can move much more slowly than the public demand,” said Wexler. “But often they achieve real results.”

CAPTION

Democrat Doug Jones won Alabama’s U.S. Senate seat Tuesday. A cooking fire at a homeless encampment caused the Skirball fire, officials said. San Francisco Mayor Ed Lee, 65, died Tuesday. House Democrats called for an investigation into allegations of sexual misconduct by President Trump.

Democrat Doug Jones won Alabama’s U.S. Senate seat Tuesday. A cooking fire at a homeless encampment caused the Skirball fire, officials said. San Francisco Mayor Ed Lee, 65, died Tuesday. House Democrats called for an investigation into allegations of sexual misconduct by President Trump.

CAPTION

Democrat Doug Jones won Alabama’s U.S. Senate seat Tuesday. A cooking fire at a homeless encampment caused the Skirball fire, officials said. San Francisco Mayor Ed Lee, 65, died Tuesday. House Democrats called for an investigation into allegations of sexual misconduct by President Trump.

Democrat Doug Jones won Alabama’s U.S. Senate seat Tuesday. A cooking fire at a homeless encampment caused the Skirball fire, officials said. San Francisco Mayor Ed Lee, 65, died Tuesday. House Democrats called for an investigation into allegations of sexual misconduct by President Trump.

CAPTION

Democrat Doug Jones, whose uphill bid for U.S. Senate gathered strength when Republican Roy Moore was hit with charges of sexual misconduct with teenage girls, won Alabama’s special election Tuesday.

Democrat Doug Jones, whose uphill bid for U.S. Senate gathered strength when Republican Roy Moore was hit with charges of sexual misconduct with teenage girls, won Alabama’s special election Tuesday.

CAPTION

New York City's bomb attack suspect was allegedly inspired by Islamic State's call for attacks. The Thomas fire has grown to at least 230,000 acres. "The Shape of Water" and "Big Little Lies" led the Golden Globe nominations anounced Monday. Mario Batali stepped away from "The Chew" and his day-to-day business operations.

New York City's bomb attack suspect was allegedly inspired by Islamic State's call for attacks. The Thomas fire has grown to at least 230,000 acres. "The Shape of Water" and "Big Little Lies" led the Golden Globe nominations anounced Monday. Mario Batali stepped away from "The Chew" and his day-to-day business operations.

CAPTION

Santa Barbara County is under siege from the Thomas fire. From the GOP's perspective, Alabama's Senate race will yield one of two unhappy results. The Weingart Center wants to reshape skid row's skyline. If lawmakers can agree on a tax bill, will you owe more or less?

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CAPTION

An explosive device exploded near Times Square during the morning rush hour Monday, injuring four people and snarling Manhattan transit, authorities said. Mayor Bill de Blasio described it as a terrorist act.

An explosive device exploded near Times Square during the morning rush hour Monday, injuring four people and snarling Manhattan transit, authorities said. Mayor Bill de Blasio described it as a terrorist act.